I write about energy and industrials for City A.M. I'm particularly interested in geopolitics, energy policy and, of course, the ever lively oil markets.

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Jessica Morris

Fridman must sell his North Sea oil fields (Source: Getty)

Unfortunate news for Russian tycoon Mikhail Fridman: the government has threatened to revoke the licenses of a dozen North Sea gas fields belonging to his investment vehicle, L1 Energy, unless they're sold.

The Department of Energy and Climate Change said LetterOne, the owner of subsidiary L1, must sell the oil and gas fields within three months - although it also offered to extend this period to six months.

"Under the terms of the licenses held by Dea UK, Dea UK and LetterOne now have three months to effect a further change of control," it said.

"However, the Secretary of State has offered to extend this period to six months and he awaits LetterOne’s response to this offer."

This led the government to voice concerns over the potential impact of sanctions on Russia - imposed due to conflict in Ukraine - and what would happen if they were tightened and ended up affecting Fridman's businesses.